Helpful articles on angel investing in general:
Why Angels Investors Don't Make Money
Angels Investors Do Make Money - 2.5x
Lean Startup Book and Uncensored Talk
Can Monkeys Pick Stocks Better than Experts?
Angel Investing Series Part II:  Due Diligence

Helpful articles on terms sheets and convertible notes:
The Truth About Convertible Debt at Startups and The HiddenTerms You Didn’t Understand
Capped Notes – The Worst of Both Worlds
4 Critical Things to Watch on your Investment Term Sheet
Convertible Debt: Worst Form Of Seed Financing — Except For All The Others
Everything You Ever Wanted To Know About Convertible Note Seed Financing
Financing Options - Preferred Stock
Financing Options - Convertible Notes
Some Thoughts on Convertible Notes
In Depth Comparison of Convertible Notes and Priced Equity

Other articles:
Everything You Wanted to know about Advisory Boards
Quora:  How much do Advisors Usually Get Paid?